2 * Copyright (c) 2007-2008
3 * Swinburne University of Technology, Melbourne, Australia.
4 * Copyright (c) 2009-2010 Lawrence Stewart <lstewart@freebsd.org>
5 * Copyright (c) 2010 The FreeBSD Foundation
8 * This software was developed at the Centre for Advanced Internet
9 * Architectures, Swinburne University of Technology, by Lawrence Stewart and
10 * James Healy, made possible in part by a grant from the Cisco University
11 * Research Program Fund at Community Foundation Silicon Valley.
13 * Portions of this software were developed at the Centre for Advanced
14 * Internet Architectures, Swinburne University of Technology, Melbourne,
15 * Australia by David Hayes under sponsorship from the FreeBSD Foundation.
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
20 * 1. Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution.
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
42 * This software was first released in 2007 by James Healy and Lawrence Stewart
43 * whilst working on the NewTCP research project at Swinburne University of
44 * Technology's Centre for Advanced Internet Architectures, Melbourne,
45 * Australia, which was made possible in part by a grant from the Cisco
46 * University Research Program Fund at Community Foundation Silicon Valley.
47 * More details are available at:
48 * http://caia.swin.edu.au/urp/newtcp/
51 #ifndef _NETINET_CC_CC_H_
52 #define _NETINET_CC_CC_H_
56 MALLOC_DECLARE(M_CC_MEM);
59 extern STAILQ_HEAD(cc_head, cc_algo) cc_list;
60 extern const int tcprexmtthresh;
62 /* Per-netstack bits. */
63 VNET_DECLARE(struct cc_algo *, default_cc_ptr);
64 #define V_default_cc_ptr VNET(default_cc_ptr)
66 VNET_DECLARE(int, cc_do_abe);
67 #define V_cc_do_abe VNET(cc_do_abe)
69 VNET_DECLARE(int, cc_abe_frlossreduce);
70 #define V_cc_abe_frlossreduce VNET(cc_abe_frlossreduce)
72 /* Define the new net.inet.tcp.cc sysctl tree. */
74 SYSCTL_DECL(_net_inet_tcp_cc);
77 /* For CC modules that use hystart++ */
78 extern uint32_t hystart_lowcwnd;
79 extern uint32_t hystart_minrtt_thresh;
80 extern uint32_t hystart_maxrtt_thresh;
81 extern uint32_t hystart_n_rttsamples;
82 extern uint32_t hystart_css_growth_div;
83 extern uint32_t hystart_css_rounds;
84 extern uint32_t hystart_bblogs;
86 /* CC housekeeping functions. */
87 int cc_register_algo(struct cc_algo *add_cc);
88 int cc_deregister_algo(struct cc_algo *remove_cc);
91 #if defined(_KERNEL) || defined(_WANT_TCPCB)
93 * Wrapper around transport structs that contain same-named congestion
94 * control variables. Allows algos to be shared amongst multiple CC aware
98 void *cc_data; /* Per-connection private CC algorithm data. */
99 int bytes_this_ack; /* # bytes acked by the current ACK. */
100 tcp_seq curack; /* Most recent ACK. */
101 uint32_t flags; /* Flags for cc_var (see below) */
102 int type; /* Indicates which ptr is valid in ccvc. */
103 union ccv_container {
105 struct sctp_nets *sctp;
107 uint16_t nsegs; /* # segments coalesced into current chain. */
108 uint8_t labc; /* Dont use system abc use passed in */
112 #define CCF_ABC_SENTAWND 0x0001 /* ABC counted cwnd worth of bytes? */
113 #define CCF_CWND_LIMITED 0x0002 /* Are we currently cwnd limited? */
114 #define CCF_USE_LOCAL_ABC 0x0004 /* Dont use the system l_abc val */
115 #define CCF_ACKNOW 0x0008 /* Will this ack be sent now? */
116 #define CCF_IPHDR_CE 0x0010 /* Does this packet set CE bit? */
117 #define CCF_TCPHDR_CWR 0x0020 /* Does this packet set CWR bit? */
118 #define CCF_MAX_CWND 0x0040 /* Have we reached maximum cwnd? */
119 #define CCF_CHG_MAX_CWND 0x0080 /* CUBIC max_cwnd changed, for K */
120 #define CCF_USR_IWND 0x0100 /* User specified initial window */
121 #define CCF_USR_IWND_INIT_NSEG 0x0200 /* Convert segs to bytes on conn init */
122 #define CCF_HYSTART_ALLOWED 0x0400 /* If the CC supports it Hystart is allowed */
123 #define CCF_HYSTART_CAN_SH_CWND 0x0800 /* Can hystart when going CSS -> CA slam the cwnd */
124 #define CCF_HYSTART_CONS_SSTH 0x1000 /* Should hystart use the more conservative ssthresh */
126 /* ACK types passed to the ack_received() hook. */
127 #define CC_ACK 0x0001 /* Regular in sequence ACK. */
128 #define CC_DUPACK 0x0002 /* Duplicate ACK. */
129 #define CC_PARTIALACK 0x0004 /* Not yet. */
130 #define CC_SACK 0x0008 /* Not yet. */
131 #endif /* defined(_KERNEL) || defined(_WANT_TCPCB) */
134 * Congestion signal types passed to the cong_signal() hook. The highest order 8
135 * bits (0x01000000 - 0x80000000) are reserved for CC algos to declare their own
136 * congestion signal types.
138 #define CC_ECN 0x00000001 /* ECN marked packet received. */
139 #define CC_RTO 0x00000002 /* RTO fired. */
140 #define CC_RTO_ERR 0x00000004 /* RTO fired in error. */
141 #define CC_NDUPACK 0x00000008 /* Threshold of dupack's reached. */
143 #define CC_SIGPRIVMASK 0xFF000000 /* Mask to check if sig is private. */
147 * Structure to hold data and function pointers that together represent a
148 * congestion control algorithm.
151 char name[TCP_CA_NAME_MAX];
153 /* Init global module state on kldload. */
154 int (*mod_init)(void);
156 /* Cleanup global module state on kldunload. */
157 int (*mod_destroy)(void);
159 /* Return the size of the void pointer the CC needs for state */
160 size_t (*cc_data_sz)(void);
163 * Init CC state for a new control block. The CC
164 * module may be passed a NULL ptr indicating that
165 * it must allocate the memory. If it is passed a
166 * non-null pointer it is pre-allocated memory by
167 * the caller and the cb_init is expected to use that memory.
168 * It is not expected to fail if memory is passed in and
169 * all currently defined modules do not.
171 int (*cb_init)(struct cc_var *ccv, void *ptr);
173 /* Cleanup CC state for a terminating control block. */
174 void (*cb_destroy)(struct cc_var *ccv);
176 /* Init variables for a newly established connection. */
177 void (*conn_init)(struct cc_var *ccv);
179 /* Called on receipt of an ack. */
180 void (*ack_received)(struct cc_var *ccv, uint16_t type);
182 /* Called on detection of a congestion signal. */
183 void (*cong_signal)(struct cc_var *ccv, uint32_t type);
185 /* Called after exiting congestion recovery. */
186 void (*post_recovery)(struct cc_var *ccv);
188 /* Called when data transfer resumes after an idle period. */
189 void (*after_idle)(struct cc_var *ccv);
191 /* Called for an additional ECN processing apart from RFC3168. */
192 void (*ecnpkt_handler)(struct cc_var *ccv);
194 /* Called when a new "round" begins, if the transport is tracking rounds. */
195 void (*newround)(struct cc_var *ccv, uint32_t round_cnt);
198 * Called when a RTT sample is made (fas = flight at send, if you dont have it
201 void (*rttsample)(struct cc_var *ccv, uint32_t usec_rtt, uint32_t rxtcnt, uint32_t fas);
203 /* Called for {get|set}sockopt() on a TCP socket with TCP_CCALGOOPT. */
204 int (*ctl_output)(struct cc_var *, struct sockopt *, void *);
206 STAILQ_ENTRY (cc_algo) entries;
211 #define CC_MODULE_BEING_REMOVED 0x01 /* The module is being removed */
213 /* Macro to obtain the CC algo's struct ptr. */
214 #define CC_ALGO(tp) ((tp)->t_cc)
216 /* Macro to obtain the CC algo's data ptr. */
217 #define CC_DATA(tp) ((tp)->t_ccv.cc_data)
219 /* Macro to obtain the system default CC algo's struct ptr. */
220 #define CC_DEFAULT_ALGO() V_default_cc_ptr
222 extern struct rwlock cc_list_lock;
223 #define CC_LIST_LOCK_INIT() rw_init(&cc_list_lock, "cc_list")
224 #define CC_LIST_LOCK_DESTROY() rw_destroy(&cc_list_lock)
225 #define CC_LIST_RLOCK() rw_rlock(&cc_list_lock)
226 #define CC_LIST_RUNLOCK() rw_runlock(&cc_list_lock)
227 #define CC_LIST_WLOCK() rw_wlock(&cc_list_lock)
228 #define CC_LIST_WUNLOCK() rw_wunlock(&cc_list_lock)
229 #define CC_LIST_LOCK_ASSERT() rw_assert(&cc_list_lock, RA_LOCKED)
231 #define CC_ALGOOPT_LIMIT 2048
234 * These routines give NewReno behavior to the caller
235 * they require no state and can be used by any other CC
236 * module that wishes to use NewReno type behaviour (along
237 * with anything else they may add on, pre or post call).
239 void newreno_cc_post_recovery(struct cc_var *);
240 void newreno_cc_after_idle(struct cc_var *);
241 void newreno_cc_cong_signal(struct cc_var *, uint32_t );
242 void newreno_cc_ack_received(struct cc_var *, uint16_t);
244 /* Called to temporarily keep an algo from going away during change */
245 void cc_refer(struct cc_algo *algo);
246 /* Called to release the temporary hold */
247 void cc_release(struct cc_algo *algo);
249 /* Called to attach a CC algorithm to a tcpcb */
250 void cc_attach(struct tcpcb *, struct cc_algo *);
251 /* Called to detach a CC algorithm from a tcpcb */
252 void cc_detach(struct tcpcb *);
255 #endif /* _NETINET_CC_CC_H_ */